title: The effects of polymer pigmentation on fingermark development techniques.
abstract: The effectiveness of latent fingerprint development techniques is heavily influenced by the physical and chemical properties of the deposition surface. The use of powder suspensions is increasing for development of prints on a range of surfaces. We demonstrate that carbon powder suspension development on polymers is detrimentally affected by the presence of common white pigment, titanium dioxide. Scanning electron microscopy demonstrates that patches of the compound are clearly associated with increased levels of powder adhesion. Substrates with nonlocalized titanium dioxide content also exhibit increased levels of carbon powder staining on a surface-wide basis. Secondary ion mass spectrometry and complementary techniques demonstrate the importance of levels of the pigment within the top 30 nm. The association is independent of fingermark deposition and may be related to surface energy variation. The detrimental effect of the pigment is not observed with small-particle reagent (MoS2 SPR) or cyanoacrylate (superglue) fuming techniques that exploit different development mechanisms.
authors.affiliation: Experimental Techniques Centre (ETCbrunel), Brunel University, Uxbridge, Middlesex, UB8 3PH, U.K.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Bacon
authors.forename: Jesus J
authors.initials: JJ
authors.lastname: Ojeda
authors.forename: Rory
authors.initials: R
authors.lastname: Downham
authors.forename: Vaughn G
authors.initials: VG
authors.lastname: Sears
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Jones
mesh_terms: D002244:Carbon; D003116:Color; D004396:Coloring Agents; D003487:Cyanoacrylates; D003878:Dermatoglyphics; D004220:Disulfides; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008982:Molybdenum; D011108:Polymers; D011208:Powders; D018629:Spectrometry, Mass, Secondary Ion; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013535:Suspensions; D014025:Titanium; D014835:Volatilization
chemical_list: D004396:Coloring Agents; D003487:Cyanoacrylates; D004220:Disulfides; D011108:Polymers; D011208:Powders; D013535:Suspensions; C009495:titanium dioxide; C029054:ethyl 2-cyanoacrylate; D002244:Carbon; D008982:Molybdenum; D014025:Titanium; C082964:molybdenum disulfide
keywords: carbon; forensic science; latent fingerprints; polymers; powder suspension; surface chemistry